Syntagma Square (Greek: Πλατεία Συντάγματος, pronounced [plaˈtia sinˈdaɣmatos], “Constitution Square”) is the central square of Athens. The square is named after the Constitution that Otto, the first King of Greece, was obliged to grant after a popular and military uprising on 3 September 1843. It is located in front of the 19th century Old Royal Palace, housing the Greek Parliament since 1934.
Syntagma Square is the most important square of modern Athens from both a historical and social point of view, at the heart of commercial activity and Greek politics. The name Syntagma (Greek: Σύνταγμα) alone also refers to the neighbourhood surrounding the square.
Source: Wikipedia